This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. There are a number of biological and pharmacological factors, which may account for methamphetamine's high addictive potential and for its toxicity. One likely candidate is its pharmacokinetics in the brain and other organs. However, methamphetamine's pharmacokinetics in the human brain and in other organs are not known. Here we propose a systematic investigation of the uptake and kinetics of d-methamphetamine (the active isomer) in the brain and in peripheral organs with PET and carbon-11 labeled d-methamphetamine in a group of normal healthy non-drug abusing volunteers. We will also pair the brain study with a measure of dopamine transporter (DAT) availability using [11C]cocaine to measure DAT levels in the same individuals.